Could Sexuality Be Linked To Dna?

Researchers Are Finding That Genetics May Play A Part In The Mysteries Of Sexual Orientation

October 01, 2006|By ALISON FREEHLING Daily Press

One of Dennis Pendleton's brothers is gay. So is one of his nephews, the son of a different brother. So is his 28-year-old son, William, the only child from a marriage that ended in divorce.

And so is Pendleton.

After his son came out in 1995, Pendleton says he slowly realized that he had hidden an attraction to men for years. Now 53, the Portsmouth resident has been with his partner, Paul Ford, for four years. Not surprisingly, he believes there must be some genetic basis to homosexuality.

"For four people in the same family to 'choose' being gay would be a little unusual and bizarre," he said. "I believe there is a link between me and the other members of my family who are the same as me. It's a reassurance that it's not a fluke or a choice. It would just answer an awful lot of questions for an awful lot of people who are struggling."

Increasingly, scientists think Pendleton is right.

Psychiatrists once considered childhood upbringing and environment the main roots of homosexuality -- classically, Sigmund Freud's theory on boys with overbearing mothers and distant fathers. Being gay was seen as a learned behavior or a choice. Until 1973, the American Psychiatric Association classified it as a mental disorder.

But today, evidence is growing that genes can play a critical role in determining sexual preference. Many scientists believe hormone levels in the womb could matter, too. While large-scale studies remain to be done, the working conclusion is that homosexuality appears to cluster in families, but that genetics, life experiences and environmental factors such as birth order mix to varying degrees in individual cases.

Researchers now estimate that 40 percent of all cases of homosexuality are linked to genetics, or coded in genes set before birth, said Alan Sanders, the leader of a major national study on male sexual orientation.

Sanders' aim is to create a genetic map of 1,000 gay brothers that could pinpoint similarities.

More than one gene almost certainly is involved, said Sanders, a psychiatrist with the Evanston Northwestern Healthcare Research Institute in Illinois.

"I don't think there's a 'gay gene,' " he said. "We're not sure how many genes and we're not sure how they work or how they become activated, but the presence of biological factors is clear."

As Virginia and other states consider referendums on gay marriage, the political impact of such findings isn't clear-cut. Gay advocates hope they might soften opposition to marriage, adoption, domestic benefits and other rights. But as scientists point out, people could just as easily lump homosexuality with other negative inherited traits -- think alcoholism or mental illness -- and wonder about therapies to "fix" people with the gene.

"It all depends on who you are and where you're coming into the debate," said Daryl Bem, a Cornell University psychologist who studies the role of childhood temperament in sexuality. "If you're pro-gay already, you'd look at being gay like being left-handed. If you're not, you'd still believe it's something that should be stamped out."

What the research could do on a personal level is clearer. Nancy, a Newport News resident with two gay sons, simply wants to understand her children better.

"I want to know if it was me or the way I raised them, or the fact that their dad wasn't around much," said Nancy, who asked that her last name not be used because her parents aren't aware of her sons' sexuality. "Or is it truly something that can't be avoided or changed? You hear all the gay jokes and the kidding around. But when it involves you and people you love, you feel very different."

When her older son told her he was gay shortly after graduating from high school, Nancy wondered if it might be a phase. She was part of the 39 percent of Americans who, according to a 2001 Gallup poll, suspect people are "made" gay by environment, not born that way.

"I remember I was digging a grave for my dog that had just died, and I was thinking, 'I'm just going to keep digging and looking down and not react or say the wrong thing,' " she said. "It took a little while to sink in. I was in denial a good six months and thinking it was something he would grow out of. I just think how much easier it would have been if we knew more about why people are gay."

The research into biology is slow and, so far, not conclusive. Scientists also stress that because gay people have as wide a range of personalities, lifestyles and interests as straight people do, many won't fit into neat theories about sexual orientation.

Still, a milestone in biological research came in 1991 when a California neuro- scientist discovered part of the brain believed to control sexual behavior was twice as large in heterosexual men as in homosexual men.